· Make sure the bobbin case is empty before trying to fill another bobbin. If there is a bobbin left in the bobbin case when winding a new bobbin a thread jam will occur in the bobbin case. Congratulations! You just broke it! | · Make sure the bobbin case is empty before trying to fill another bobbin. If there is a bobbin left in the bobbin case when winding a new bobbin a thread jam will occur in the bobbin case. Congratulations! You just broke it! |